CLASS DISCUSSION

The DISCUSSION to be held in class will be based on three short but important papers that appeared in the journal Science in 2003. Together, they provide a good overview of present problems and proposed solutions. Read the papers and come to class prepared to discuss the following questions. If you have other ideas, we can certainly consider them.

1) How have our perspectives of reef decline changed over the years?
2) What is pristine? How do the views reflected in these papers bear on this? How should we take this into account when considering ways to mitigate reef decline?
3) What are the pro's and cons of the top-down vs bottom-up approaches that are discussed (which is which)?
4) Who's ideas resonate more strongly with you?
5) What do we need to do that might make a difference in the VERY short time left for the world's coral reefs?
6) Should we bother? Why or why not?

Some hints for reading the articles:

Hughes et al, 2003, "Climate Change, Human………….."

This is a general summary of the present situation. I'd start with this one as it is more narrative. Think about what the impacts are, how our sense of scale has changed more recently, and what the appropriate sorts of responses might be. In particular, make sure you understand the concept of MPA's vs NTA's and how they relate to top-down vs bottom-up strategies. How do these fit into the mitigation strategy?

Pandolfi et al 2003, "Global Trajectories….."

This paper discusses the concept of "pristine" reefs. In Figure 1 (x-axis), think of A (agriculture) as 3,500 years ago, M1 as 1900 and M2 as 1950. Look at the first lighter-colored band (Depleted). If it is shifted to the left, depletion occurred earlier - to the right, later. The bands slope, because the graph also considers the percent of reefs in a certain category (i.e., 1% of the world's reefs will be depleted before 10% are).

Figure 2 shows the trajectory if 14 sites they examined historically. The figures are in color, so you'll need to look at them on the computer or print them on a color printer to get the full effect. Basically, the figure shows when particular reefs reached some state. Use the same time boundaries as before. Don't worry about what PCA is (it's a statistical method), but think of anything over 0 as "in pretty tough shape", and anything over 4 as "close to gone". What reefs are further along, and why?

This is summarized in Figure 3, which shows that some reefs were almost 80% degraded by the 1950's, when we started looking at reefs. What was the best condition of reefs at that time? What made us think these reefs were pristine? What was still left? What does this say about our present view ofr reefs? What should and can we do – and why?

Aronson et al, 2003, Cause of Coral Reef Degradation,
This is a letter to Science in response to the above two papers, so I'd read it last. Obviously, they have issues with both papers, either separately or together. Responses from the authors are also provided. In total, these papers give you a good idea of the spectrum of opinions on how reefs work, how they have declined, and what we might consider to fix them.